1. Field of the Invention
The present invention relates to a route guidance learning device contrived to learn in what way a vehicle deviated from a route in the past, and to correct its guidance method at all times.
2. Description of the Related Art
A navigation system for a vehicle informs a user via voice or visual display that the user has to go straight, turn to the right, or turn to the left short of an intersection when a running vehicle approaches the intersection. The system prevails that the guidance information is given to a user at the predetermined timing short of the intersection. Therefore, there is a circumstance in which timing may not necessarily be said to be appropriate, depending on a driver's driving skill and the sense of distance.
As a prior art achieved success in curing this defect, a device has been proposed which is disclosed in JP 05-232873 A in which the device is arranged such that it calculates an arrival distance or an arrival time from the current position of a vehicle to an intersection lying on a route on the basis of road map data, outputs guidance information when the calculated value comes to the previously set distance or time, as well as arbitrarily sets the distance or time, and outputs guidance information at the timing according to a driver's skill and the sense of distance.
The conventional device thus arranged as above has been proposed, however, the device entails a drawback that it causes inconvenience to a user of previously inputting an arrival distance or an arrival time, and further it is difficult for a user who inputs a value to judge whether or not an input value is really proper.
Therefore, when an value input by a user is improper, a vehicle can deviate from the prescribed route. In this case, information indicating in what way a vehicle deviated from a route is by no means reflected upon the next route guidance in order to automatically correct a route guidance. For this reason, when a user takes the same route again, the user is in danger of repeatedly committing a similar deviation from a route to the past.